This invention relates to signalling devices for signalling a condition to an observer and more particularly to railway signalling devices for signalling a condition of a railroad track to a train engineer situated on a train.
Generally, all railways have an authority which issues operating rules of the railway. Such rules often have specific clauses which protect workers performing track work within certain limits along railway rights-of-way during a pre-determined period of time. A typical clause is that before any work can be performed at a work site, a flagman is required to walk along the track to a location at a specified distance from the work site and physically place four flags on staffs in a position so as to be seen by train engineers on approaching trains. When the work shift is completed, the flagman is sometimes required to remove the flags. On successive days, the flagman is required to place the flags at the start of each shift and is required to remove the flags at the end of each shift. This can be time consuming for the flagman as the location of placing the flags is often a considerable distance from the work site.
What is desired therefore is a device which eliminates the task of physically placing flags at the required locations along a railroad track when work is to be performed along railway rights-of-way.